To analyze a protein of interest, it is necessary to develop reagents that can detect it. Furthermore, to investigate the role of a protein in rheumatic disease models, it is frequently desirable to inject monoclonal antibodies (mAbs) or recombinant proteins that block the function of the protein in question. The Protein Core thus will be established to provide services through a 1) Hybridoma facility to produce mAbs; and 2) Production and Purification facility to produce high quality purified mAbs or recombinant proteins of interest. The production of new mAbs will take place in an established hybridoma facility that is particularly expert in generating Armenian hamster mAbs against mouse antigens. New services are planned including the development of rabbit hybridomas. The Production and Purification Facility will be newly established by first generating large quantities of purified mAbs from hybridomas using Protein A affinity chromatography. Other mAbs that are routinely used by RDCC investigators will be produced in large quantities and then purified. Once established, the facility will develop new services to produce large quantities of recombinant proteins carrying tags such as Fc, myc, and 6-His. Subsequent purification can then use standard affinity chromatography protocols. Thus, the facility will provide investigators with large quantities of proteins that can be used to analyze their molecules in relationship to rheumatic disease models.